And the walls came tumbling down

I feel bad
And sometimes people notice, which I am so greatful for.
And they say, "Are you okay?"
And I say
"Yeah, I'm just really tired"
And they smile and leave me alone.
I don't know how to tell them when I'm not okay... I don't know how not to lie.
I've lied so much.
I don't recognize the truth anymore.

I know I'll be okay, but there are moments, or days, or weeks, or months, when I'm almost all the way at the bottom. Even in those times, I must subconsciously know I'll eventually float back up again, otherwise I'd be dead. But those are the times when I'm really not okay, and I'm really not just tired, and I really need something. But I don't know what yet.
And I think maybe I could figure out what I need if I get to know myself a little better.